The island in the middle of San Francisco Bay where the city plans to build a second downtown was once home to military training schools and ship operations that included dangerous radioactive substances including radium, cesium and plutonium. The U.S. Navy says there is now no risk to the island's residents, as the island is prepared for even more construction. Yet in March, 2014, the military announced that it will test residents' homes for radioactive waste. Experts question whether the Navy's investigation will permit and include independent research, investigation and findings in addition to the Navy's testing and what the military use and history of Treasure Island means for the island and for San Francisco Bay.